Inhibition of glycogen synthase kinase-3ß by falcarindiol isolated from Japanese Parsley (Oenanthe javanica).

A new biological activity of falcarindiol isolated from Japanese parsley (Oenanthe javanica) using the mutant yeast YNS17 strain (zds1Δ erg3Δ pdr1Δ pdr3Δ) was discovered as an inhibitor of glycogen synthase kinase-3ß (GSK-3ß). Falcarindiol inhibited GSK-3ß in an ATP noncompetitive manner with a Ki value of 86.9 µM using a human enzyme and luminescent kinase assay platform. Falcarindiol also both suppressed gene expression of glucose-6-phosphatase (G6Pase) in rat hepatoma H4IIE cells and protected mouse neuroblastoma HT22 cells from glutamate-induced oxidative cell death at 10 µM. During an oral glucose tolerance test (OGTT), the blood glucose level was significantly decreased in the rats treated with oral administration of O. javanica extract containing falcarindiol (15 mg/kg). These findings indicate that Japanese parsley could be a useful food ingredient against type-2 diabetes and Alzheimer's disease.

Probucol markedly reduces HDL phospholipids and elevated prebeta1-HDL without delayed conversion into alpha-migrating HDL: putative role of angiopoietin-like protein 3 in probucol-induced HDL remodeling.

Probucol is a unique hypolipidemic agent that increases cholesteryl ester transfer protein (CETP) activity. Enhanced CETP-mediated conversion of high-density lipoprotein (HDL) partly explains the probucol-induced decrease in HDL cholesterol and increase in plasma prebeta1-HDL (native lipid-poor HDL) concentrations. However, HDL cholesterol is reduced in patients that are completely deficient in CETP. Angiopoietin-like protein 3 (ANGPTL3) is an endogenous suppressor of endothelial lipase that promotes the hydrolysis of HDL phospholipids and may generate prebeta1-HDL. To determine whether probucol decreases ANGPTL3 and HDL phospholipids while increasing prebeta1-HDL, we measured these parameters before and after a 4-week probucol treatment in 39 hypercholesterolemic patients and age- and sex-matched controls. The median ANGPTL3 had decreased from 143 to 113 microg/L by week 4 (p<0.05). High-performance liquid chromatography revealed that probucol decreased the phospholipid content of very large (13.5-15 nm) and large (12.1 nm) HDL particles predominantly by 65% (p<0.01) and 53% (p<0.001), respectively. The change in ANGPTL3, but not CETP mass, was positively correlated with that in large HDL phospholipids (r=0.455, p<0.05). The absolute and relative concentrations of prebeta1-HDL increased by 14% (p<0.01) and 60% (p<0.001), respectively. The conversion rate of prebeta1-HDL into alpha-migrating HDL by lecithin-cholesterol acyltransferase did not change significantly. In conclusion, probucol decreases plasma ANGPTL3 and HDL phospholipids while increasing prebeta1-HDL. We speculate that probucol induces HDL remodeling via an endothelial lipase-mediated pathway.